While many things remain unknown about the conclusion to Yemen’s current political crisis, one thing is clear: developments are simply too fast-moving and too complex for anyone to predict the next turn, much less the final outcome. Based on recent events, however, it is possible to consider worst case scenarios of violence or chaos, and best case scenarios for a new social contract pointing towards a more democratic future.

Here’s the background to this week’s news, in a nutshell. At least since President Ali Abdallah Salih restored unity by force during a short civil war in 1994, Yemen has staggered under odious burdens of rising poverty, inequality, corruption, cronyism, political de-liberalization, economic disinvestment, and ecological degradation. In power since early 1979 in North Yemen and seemingly determined to rule for life, prepare his favorite son Ahmad Ali Salih as his heir, and retain a monopoly of seats for his ruling General People’s Congress in an increasingly impotent parliament, the president derailed a functioning competitive multiparty electoral process.

Southerners living in what had been the People’s Democratic Republic (PDRY) prior to 1990, having failed in the 1994 secessionist bid, have been protesting for several years against material deprivation and military repression. Discontent simmered in the former North where Ali Abdallah Salih had ruled since 1978, too. The regime battled a localized al-Huthi insurgency in Sa’ada province up towards the Saudi border, claiming the Zaydi Shi’a rebels were inspired by Iran. Both the "harak" (movement) in the former South and the al-Huthi rebellion considered their grievances to be separate from those of the rest of the country, and the regime successfully portrayed them as isolated, illegitimate throw-backs to the PDRY and the Zaydi imamate, respectively, that threatened the unity of the republic. But across the country citizens were alienated, frustrated, and miserable.

The popular revolts that toppled Tunisian and Egyptian dictators in early 2011 inspired Yemenis. Bypassing the formal opposition coalition of the so-called Joint Meeting Parties, mostly youthful demonstrators thronged to public squares. Although in contrast with Tunisia, Egypt, and Bahrain they couldn’t assemble in fantastic and photogenic numbers in a single central metropolitan area, in a half-dozen major cities and a number of small towns constituted themselves as a nationalist pro-democracy movement. They chanted the North African slogans, "Irhal" and "Isqat al-Nizam," calling for the immediate removal of the president and his whole regime. In response to violent attacks by purported pro-regime counter-demonstrators, they mockingly turned the slogan around: "al-nizam yurid isqat al-sha’ab:" the regime wants the downfall of the people.

Notwithstanding President Salih’s vague promises of an electoral transition in 2013, demonstrations persisted, spread, and expanded. Some members of parliament, the ruling General People’s Congress (GPC), and the administration quit in solidarity with "the youth." Even some prominent shaykhs of the president’s own Hashid tribal confederation declared their sympathies with the rebels.

Last Friday, March 18, in a pitch of fury or panic someone ordered snipers to open fire on demonstrators near Sana’a University. The next day, at least 50 lay dead, and others mortally wounded. In disbelief, anger, and grief, a record 150,000 marched in Sana’a’s biggest day of rage so far.

Senior diplomats, ministers, ruling party members, and civil servants resigned en masse. Most striking were defections from within the military, long the main base of Salih’s support. Most ominously for Salih, Major-General Ali Muhsin (al-Ahmar), a regime stalwart and top commander who pitilessly prosecuted the 1994 campaign against the South and the war against the al-Huthis, announced his support for the demonstrators. Launching a partial military revolt, he ordered his tank units to defend the demonstrators even as the Republican Guard under Ahmad Salih positioned itself around the massive presidential compound. The reformists are wary of a wolf in lamb’s clothing.

What, then, are the possible scenarios for the coming days, weeks, or months? Quite a few are circulating already, mostly quite dire. The mutineers could clash with the American-armed Republican Guard led by Ahmad Ali Salih and other forces headed by members of the Salih family. An Ali Muhsin victory would amount to a military coup d’etat at the hands of a new dictator no less savory or popular than President Salih or his son. Prolonged battle could destroy the country or collapse the state. The former PDRY could re-declare its sovereignty. Other regional or tribal aspirations for autonomy could come to the fore. There could be a free-for-all reminiscent of Somalia, or as in Libya rebels could take some territory as the old regime unleashes its fury on the population in those areas. It’s impossible to predict the outcome of a fight to the finish, except that more blood would be shed.

Any of these outcomes would turn Yemenis’ dreams of freedom into nightmares of tyranny and/or anarchy. Other Arab reformers rooting for liberalization would be disheartened. Warfare or chaos in Yemen could also potentially threaten the stability of neighboring Saudi Arabia, embolden radical jihadists in the Peninsula, and thus ultimately endanger the interests of the United States.

But things don’t need to turn out badly for Yemen, its neighbors, and America. What are the alternatives? Best-case scenarios seem contingent on Salih following Ben Ali and Mubarak’s example rather than Qaddafi’s. If he resigns immediately, power could be transferred to a technocratic, civilian transitional government. New parliamentary and presidential elections could be organized in a matter of months. This transition would be easier in some ways than Egypt’s because there are already organized, legal political parties in Yemen (the several JMP parties and perhaps a reconstituted GPC). Since the existing multiparty electoral process has been suspended rather than irretrievably despoiled, it could be resuscitated.

It might be desirable to amend the constitution, as Salih himself recently offered to do by way of feeble concessions, such that the country is run by a parliamentary rather than a presidential system. But unlike Egypt, Yemen would not have to change the constitution before holding elections. Instead of quick piecemeal amendments, Yemenis could re-constitute a contemporary version of the National Dialogue of Political Forces that held mass conferences and scholarly workshops nationwide in 1993 and early 1994 and eventually offered social contract and constitutional proposals in papers the most comprehensive of which was called the Document of Pledge and Accord. That effort, which failed to thwart the 1994 civil war, could be restarted now to engage the street protesters in a genuine civic conversation about necessary reforms and help envision a national path towards more democratic, just, transparent, responsible civilian governance.

This is a tall order, but it is do-able. It is the best case scenario for angry yet hopeful Yemenis who have put their lives on the line, for the now-beleaguered pan-Arab pro-democracy movement, and ultimately for America. Under its counter-terrorism strategy during the past couple of years the U.S. spent hundreds of millions of dollars bolstering a corrupt military dictatorship that backtracked on reforms, muzzled the press, disregarded popular aspirations, and resorted to extra-judicial detentions and even executions.

Backing an economically, politically, environmentally, and ethically unsustainable status quo will not make Americans safer or win hearts and minds in Arabia; it will put the United States on the wrong side of history and could even give comfort to our worst enemies. The Obama administration and other Western governments must announce an immediate suspension of military aid to the Salih government and bring all possible diplomatic pressure to bear to convince President Salih that the time has come for him to relinquish power.

Sheila Carapico is professor of political science at the University of Richmond and the American University in Cairo.